Wedding dresses are the most popular type of dress in the movie '27 Dresses'. These dresses are typically white or ivory and are worn by brides on their wedding day. They come in a variety of styles, including ballgown, mermaid, A-line, and sheath. Wedding dresses are often adorned with lace, beading, or other embellishments to add a touch of elegance. They are designed to make the bride feel beautiful and special on her big day.